1. Field of the Invention
The present invention relates to an ink tank coupling method for use with a liquid ejection recording apparatus in which a liquid such as ink is ejected to carry out recording, an ink jet recording apparatus, and an ink tank for use in the ink jet recording apparatus. More particularly, the present invention relates to an ink tank coupling method for use with a liquid ejection recording apparatus which is employed in an ink jet printing system consuming a large amount of ink, an ink jet recording apparatus, and a large-capacity ink tank mounted on the ink jet recording apparatus.
2. Description of the Related Art
An ink tank (liquid storing container) for use in an ink jet recording apparatus is constructed to be detachably attached to an ink tank unit, which serves as an ink tank receiving portion of the recording apparatus, in order that the ink tank can be easily replaced-when ink is exhausted. The ink tank has an ink supply port which is closed by a rubber plug to prevent leakage of ink when the ink tank is handled alone. The ink tank unit includes a hollow needle or the like which is provided in its connecting portion to the ink tank. By connecting the ink tank unit to the ink supply port of the ink tank, ink can be supplied from the ink tank.
Japanese Patent Laid-Open No. 1-141750, for example, discloses a detailed construction of an ink tank unit which enables such an ink tank to be mounted on an ink jet recording apparatus, and an ink tank coupling method. According to the known related art as disclosed in that publication, the ink tank has an ink supply port provided in its front portion taking in the direction in which the ink tank is inserted into the ink tank unit so that the direction in which the ink tank is inserted into the ink tank unit is the same as the direction in which the ink supply port of the ink tank is connected to an ink supply path in the ink jet recording apparatus. When coupling the ink tank unit and the ink tank with each other, positioning of the ink tank relative to the ink tank unit and insertion of the hollow needle into the ink supply port are effected with one action.
The direction in which the ink tank is inserted into the ink tank unit depends on the shape and size of the ink tank. In some cases, the ink tank is horizontally inserted into the ink tank unit as disclosed in the above-mentioned Japanese Patent Laid-Open No. 1-141750, and in other cases, the ink tank is ventrally inserted into the ink tank unit from above as disclosed in Japanese Patent Laid-Open No. 9-076525. In any case, the direction in which a needle is inserted is opposed to the direction in which the ink tank is inserted.
Meanwhile, in a large-sized ink jet recording apparatus having a high printing duty and consuming a large amount of ink, a large-capacity ink tank capable of containing an amount of ink, for example, not less than 200 cc, more preferably not less than 500 cc, is often employed to hold down the frequency of replacement of ink tanks.
With a container having such a large size, however, the following specific problems due to an increase of the container size arise in point of connection to an ink tank unit.
Specifically, because the container contains a large amount of liquid and the container including the liquid has large total weight, users sometimes cannot clearly recognize whether an ink supply needle is appropriately connected at the same time as upon the container being attached to the ink tank unit, including even the case that the needle and an ink supply port are shifted in positional relationship between them. As a result, an extra force is imposed on a coupled portion between the container and the ink supply unit due to a condition where the needle and the ink supply port are not positively connected to each other. This raises a risk that ink may leak from the coupled portion, or in the worst case, the coupled portion may be damaged; for example, the needle may be bent.
Also, because of the above-mentioned container having a large size, if an ink tank is designed to be positioned to a point remote from the coupled portion when attached to the recording apparatus, the container is required to be manufactured with high accuracy in order to realize positive coupling.
Particularly, in such a construction that the direction in which the needle is inserted is opposed to the direction in which the ink tank is inserted, if the ink tank is fixed offset from a predetermined position, an extra force is imposed on the coupled portion due to a condition where the needle and the ink supply port are not positively connected to each other, thus resulting in a risk that ink may leak from the coupled portion, or in the worst case, the coupled portion may be damaged; for example, the needle may be bent.
A first object of the present invention is to solve the problems set forth above, and to provide an ink tank coupling method, an ink jet recording apparatus, and an ink tank, by which position accuracy of a coupled portion between an ink tank and an ink tank unit is improved to enhance reliability of the coupling with a relatively simple construction, while allowing users to recognize the proper coupling of the ink tank.
A second object of the present invention is to, in addition to or apart from the above first object, provide an ink tank coupling method, an ink jet recording apparatus, and an ink tank, by which position accuracy of a coupled portion between an ink tank and an ink tank unit is improved to enhance reliability of the coupling with a relatively simple construction.
Still another object of the present invention is to, in addition to or apart from the above first and second objects, provide an ink tank which can protect an ink supply port against an external shock caused upon a drop so that the ink tank is more positively coupled to a recording apparatus capable of mounting the ink tank on it.
To achieve the above first object, the present invention provides an ink tank coupling method for an ink jet recording apparatus comprising a recording head for ejecting ink to carry out recording, an ink supply needle for supplying the ink to the recording head, and moving means for moving the ink supply needle to a predetermined position, the ink jet recording apparatus being able to detachably mount an ink tank containing ink supplied to the recording head, the method comprising a holding and fixing step of holding and fixing the ink tank to a predetermined position by releasing movement preventing means which prevents movement of the ink supply needle caused by the moving means, and pressing the ink tank to abut a reference surface with an operation of attaching the ink tank to the ink jet recording apparatus, and an ink supply needle inserting step of inserting the ink supply needle to the predetermined position in the ink tank by the moving means after the holding and fixing step.
Also, the present invention provides an ink jet recording apparatus comprising a recording head for ejecting ink to carry out recording, an ink supply needle for supplying the ink to the recording head, and moving means for moving the ink supply needle to a predetermined position, the ink jet recording apparatus being able to detachably mount an ink tank containing ink supplied to the recording head, wherein the ink jet recording apparatus further comprises a reference surface against which the ink tank is fixedly held, and movement preventing means for preventing movement of the ink supply needle caused by the moving means, the movement preventing means being released upon the ink tank being attached to the ink jet recording apparatus.
According to the ink tank coupling method and the ink jet recording apparatus set forth above, it is possible to avoid a risk that may injure users due to such a false operation as when any other ink tank than desired is inserted, and to keep the needle from being damaged. Further, since the needle is inserted after a coupling portion of the ink tank has been positioned, positional accuracy of coupling portions of the ink tank and an ink tank unit of the recording apparatus can be increased to improve reliability of the coupling, and users can recognize that the ink tank has been coupled to the ink tank unit.
The first object of the present invention can be achieved by the ink tank coupling method and the ink jet recording apparatus set forth above. In addition, the following specific advantages can be obtained by meeting more preferable conditions below.
One of the more preferable conditions is that a direction of insertion of the ink tank is substantially perpendicular to a direction of insertion of the ink supply needle. This feature provides an advantage that the insertion of the ink supply needle does not affect the ink tank in the direction of insertion of the ink tank in which the position of the ink tank is more likely to shift, and therefore more positive coupling is realized. Further, with the above feature, a connecting portion of the ink tank to the exterior can be disposed at the top of the ink tank, and ink leakage can be avoided effectively.
Also, by preventing wrong attachment of the ink tank before releasing the movement preventing means, the ink tank can be more reliably prevented from being attached falsely.
By providing at least two types of the movement preventing means in the holding and fixing step, the needle is avoided from being damaged inadvertently even if one of the movement preventing means should malfunction, and the movement preventing means can be constructed to have increased strength.
By urging the ink tank by the moving means in a direction to abut the reference surface, more positive coupling can be realized.
On the other hand, to achieve the above second object, the present invention provides an ink tank coupling method for an ink jet recording apparatus comprising a joint needle capable of being connected to an ink tank containing ink used for recording, and moving means for moving the joint needle to a predetermined position, the ink jet recording apparatus being able to detachably hold the ink tank provided with a projected portion for connection to the joint needle, the method comprising a pressing step of inserting the ink tank in a direction perpendicular to the direction in which the needle is moved by the moving means, and pressing the projected portion to abut a reference surface parallel to the direction of movement of the needle.
Also, the present invention provides an ink jet recording apparatus comprising a joint needle capable of being connected to an ink tank containing ink used for recording, moving means for moving the joint needle to a predetermined position, holding means being able to detachably hold the ink tank provided with a projected portion for connection to the joint needle, and a reference surface against which the projected portion is fixedly held, wherein a direction of movement of the joint needle caused by the moving means is perpendicular to a direction of insertion of the ink tank into the holding means, and is parallel to the reference surface.
According to the ink tank coupling method and the ink jet recording apparatus set forth above, since the direction of insertion of the ink tank is substantially perpendicular to the direction of insertion of the needle caused by the moving means, the insertion of the needle does not affect the ink tank in the direction of insertion of the ink tank in which the position of the ink tank is more likely to shift, and therefore more positive coupling is realized. Further, since a connecting portion of the ink tank to the exterior can be disposed at the top of the ink tank, ink leakage can be avoided effectively. Since the ink tank is positioned with the aid of the projected portion which serves as a coupling portion to the recording apparatus, it is possible to increase positional accuracy of the coupling portions of the ink tank and the ink tank unit and to improve reliability of the coupling by increasing accuracy of a part of the tank, i.e., the projected portion, rather than accuracy of the entire tank.
The second object of the present invention can be achieved by the ink tank coupling method and the ink jet recording apparatus set forth above. In addition, the following specific advantages can be obtained by meeting more preferable conditions below.
One of the more preferable conditions is that the reference surface comprises a first reference surface perpendicular to the direction of insertion of the ink tank, and a second reference surface perpendicular to the first reference surface, and the pressing step includes a first pressing step of pressing the projected portion to abut the first reference surface, and a second pressing step of pressing the projected portion to abut the second reference surface. This feature further increases the positional accuracy.
Further, when coupling an ink tank including a plurality of projected portions, one of the plurality of projected portions is pressed to abut the first reference surface, and at least two of the plurality of the projected portions are pressed to abut the second reference surface. With this feature, in an ink jet recording apparatus which employs inks of multiple colors, the ink tank can be prevented from wobbling in the direction of insertion thereof and more positive coupling can be realized without wasteful use of a space. In this connection, by constructing the holding means to include, as a pressing means, a click member for urging the projected portions which abuts the first reference surface, users can sense a more positive click feel and can more easily recognize that the ink tank has been positioned.
Moreover, the present invention provides an ink tank for use in the ink jet recording apparatus set forth above.
According to the present invention, in an ink tank including an ink containing portion for containing ink, the ink tank comprises a substantially cylindrical first projected portion having a communicating portion for communicating the ink containing portion with the exterior, and a substantially cylindrical second projected portion having a communicating portion for leading out the ink in the ink containing portion to the exterior, the first and second projected portions being both provided on a surface opposing to a bottom surface of the ink tank, a grip portion provided at a rear end of the ink tank in the direction of insertion thereof, and a vertical surface portion extending upward from the grip portion perpendicularly to the bottom surface of the ink tank in an opposed relation to the first and second projected portions, the second projected portion being provided in an area between the vertical surface portion and the first projected portion, the vertical surface portion having an upper end at a higher level from the bottom surface than end faces of the communicating portions of the first and second projected portions, the second projected portion being positioned at a level lower than a line connecting the upper end of the vertical surface portion and the end face of the communicating portion of the first projected portion.
With the ink tank set forth above, since the second projected portion for supplying the ink is positioned at a level lower than the line connecting the upper end of the vertical surface portion and the end face of the communicating portion of the first projected portion, the second projected portion is prevented from directly contacting the ground and is protected in the even of drop of ink tank. Therefore, an ink tank is provided which can be more reliably coupled to a recording apparatus capable of mounting the ink tank on it.
A desired construction for protecting the second projected portion more reliably can be obtained by providing a slope between the vertical surface portion and the surface opposing to the bottom surface, and a rib on the slope.
Further, by causing the moving means to urge the vertical surface portion of the ink tank in a direction to abut the reference surface, there is provided an ink tank which can be more positively coupled to the recording apparatus set forth above. Here, the communicating portion of the ink tank of the present invention may be formed as an opening beforehand, or may be sealed by a rubber plug or the like and then pierced by, e.g., an ink supply needle of an ink jet recording apparatus for communication.
According to another form of the present invention, in an ink tank including an ink containing portion for containing ink, the ink tank comprises a bottom surface provided with three projections for supporting the ink tank, an ink supply portion for leading out the ink in the ink containing portion to the exterior, a top surface opposing to the bottom surface, a plurality of lateral surfaces adjacent to the bottom surface and the top surface, the plurality of lateral surfaces including one set of opposing surfaces extended in a lengthwise direction of the ink tank, and a grip portion provided at one end of the ink tank in the lengthwise direction thereof insertion thereof, two of the three projections being provided on the bottom surface in an opposed relation in areas near the opposing surfaces of the plurality of lateral surfaces, the ink supply portion being provided in an area of the top surface opposing to an area locating on or within lines connecting the three projections.
With the ink tank set forth above, since the tank is supported by three projections, a force generated upon the insertion of the needle into the tank unit is borne by the projections rather than the entire bottom surface of the tank. It is hence possible to provide an ink tank which is less affected upon the insertion of the needle depending on product variations of ink tanks.
Note that the term xe2x80x9cinkxe2x80x9d used in this specification implies all kinds of liquids ejected from an ink jet recording head, and therefore includes, for example, a printing improvement liquid such as a treatment liquid used to improve permeation of ink into recording paper.